In an optical network field, an optical network having a complex topology such as a ring cross connection or a mesh is being developed with an OADM (Optical Add-Drop Multiplexer) device allowing add-drop of an optical signal by wavelength, path switching or the like, or a WXC (Wavelength Cross Connect) device that is named as an optical hub.
Chromatic dispersion is one of factors determining transmission quality of an optical signal in an optical network. There is an attempt that a chromatic dispersion compensation device on an optical transmission path is arranged appropriately so that a residual dispersion value of an optional wavelength path transmitted on the optical network is included in a desired dispersion tolerance and a chromatic dispersion is compensated, in order to restrain a wavelength degradation of an optical signal because of the chromatic dispersion.
International Publication No. WO 2005/006604 A1 (hereinafter referred to as Document 1) discloses a technology where a dispersion compensation amount of a chromatic dispersion compensation device on each wavelength path is determined so that a residual chromatic dispersion at each terminal of a plurality of wavelength paths extracted from an optical network is included in an allowable range of a residual chromatic dispersion determined with respect to each wavelength path, as a chromatic dispersion compensation design method for a ring cross connection or a mesh network.
However, Document 1 does not disclose a concrete solving method how to select a combination of the dispersion compensation amount of each chromatic dispersion compensation device.